If you have any questions or comments please send them to me at email@example.com.
Some people need to use p4merge instead of p4diff as the "executable" name to perform diffs with. This version still uses p4diff because that will not break existing users. If you need to use p4merge instead, I recommend that you create a p4merge script/batch file in a directory that the PATH variable points at on your system (the PATH that netbeans sees in particilar). Put the appropriate command for using p4merge into that p4diff script/batch file and you should be good to go. This is not a new issue, it's been necessary to do this for all versions.
This version finishes the work on the options dialog to make it now possible to set the perforce configuration options there, globally. If you need separate options, per project, then you need to use P4CONFIG (see the perforce web site information on P4CONFIG). There is probably still some bugs I haven't seen yet, so feel free to report them to me, or better yet, download the source and fix them and send me a diff that I can apply and update the distribution here with.